EXAFS Solids

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Cu metal

Cu, fcc metal, 4 shells. The list of atomic coordinates (ATOMS card) for crystals can be produced by the program atoms. Thus instead of giving long atoms list, we present a short ‘atoms.inp’ file. For connection with EXAFS fitting programs see FEFF Files and the PRINT card.

TITLE Cu crystal, 4 shells
* Cu is fcc, lattice parameter a=3.61 (Kittel)
*Cu at 190K, Debye temp 315K (Ashcroft & Mermin)
DEBYE 190 315 0

POTENTIALS
  0 29 Cu0
  1 29 Cu

ATOMS
atoms list generated using atoms.inp file below
--------------------------------------------
title Cu metal fcc a=3.6032
fcc ! shorthand for F M 3 M
rmax= 11.13 a=3.6032
out=feff.inp ! index=true
geom = true
atom
! At.type x y z
Cu  0.0 0.0 0.0
--------------------------------------------

YBCO High-Tc superconductor

TITLE YBCO: Y Ba2 Cu3 O7 Cu2 core hole

CONTROL 1 1 1 1 1 1
PRINT   0 0 0 0 0 0

RPATH 4.5 

POTENTIALS
* ipot  z tag
   0   29 Cu2
   1    8 O
   2   39 Y
   3   29 Cu1
   4   56 Ba

ATOMS
atoms list generated by the following atoms.inp file
-----------------------------------
title YBCO: Y Ba2 Cu3 O7 (1-2-3 structure)
space P M M M
rmax=5.2 a=3.823 b=3.886 c=11.681
core = Cu1
atom
! At.type x   y   z    tag
  Y      0.5 0.5 0.5
  Ba     0.5 0.5 0.184
  Cu     0   0   0     Cu1
  Cu     0   0   0.356 Cu2
  O      0   0.5 0     O1
  O      0   0   0.158 O2
  O      0   0.5 0.379 O3
  O      0.5 0   0.377 O4
--------------------------------------

Calculation Strategies and Examples

EXAFS calculations

  1. SF6 Molecule
  2. Solids
  3. Estimate of S20
  4. Configuration averaging over absorbers
  5. Adding self-consistency

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